3-iodo-2-propynyl butylcarbamate

Endpoint summary

Key value for chemical safety assessment

Effects on fertility

Description of key information

Based on a two generation study in rats there is no indication that the test item affects fertility when administered up to a dose of 101.2 mg/kg bw/day via the diet.

Link to relevant study records

Reference

Endpoint:

two-generation reproductive toxicity

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1986-02-06 to 1987-10-16

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EPA OPP 83-4 (Reproduction and Fertility Effects)

Version / remarks:

1982

Deviations:

no

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 416 (Two-Generation Reproduction Toxicity Study)

Version / remarks:

2001

Deviations:

no

Principles of method if other than guideline:

By the time the study was conducted the following parameters were not required and thus not determined:
- oestrus cycle
- sperm parameters

GLP compliance:

yes

Limit test:

no

Justification for study design:

SPECIFICATION OF STUDY DESIGN FOR TWO GENERATION REPRODUCTION TOXICITY STUDY:
The study was conducted in 1987 when the two generation reproduction toxicity study was an internationally recommended and accepted study type.

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Lot/batch No.of test material: P 2710-8511-R100

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Wiga GmbH
- Weight at study initiation: (P) Males: 175 - 235 g; Females: 140 - 185 g
- Housing: individually, except for mating and lactation
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: minimum 2 weeks

ENVIRONMENTAL CONDITIONS
- Temperature: 20 - 25 °C
- Humidity: 40 - 70 %
- Photoperiod: 12 / 12 hrs dark / hrs light

Route of administration:

oral: gavage

Vehicle:

unchanged (no vehicle)

Details on exposure:

PREPARATION OF DOSING SOLUTIONS:
Separate batches of diet were prepared at fixed concentrations for each treatment group. The weighed amount of test article was mixed with the final weight of the powdered diet in several steps (e.g. four steps for 30 kg formulated test article: 300 g, 5 kg, and 10 kg pre-mixture, 30 kg final mixture).

DIET PREPARATION
- Rate of preparation of diet: approx. monthly
- Mixing appropriate amounts with: powdered diet (Ssniff R 10)

Details on mating procedure:

- M/F ratio per cage: 1/1
- Length of cohabitation: up to 21 d
- Proof of pregnancy: sperm in vaginal smear referred to as day 0 of pregnancy
- After successful mating each pregnant female was caged: individually

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

As not initially requested, the diet was reformulated and test item amount was analysed for its stability over one month within the formulation.

Duration of treatment / exposure:

F0: 14 weeks pre-mating, throughout mating period and until day of necropsy (incl. pregnancy and lactation for females)
F1: from weaning until approx. 13 weeks of age, throughout mating until day of necropsy (incl. pregnancy and lactation for females)

Frequency of treatment:

daily via diet

Details on study schedule:

- Selection of parents from F1 generation when pups were approx. 21 days of age (after weaning).
- Age at mating of the mated animals in the study: not specified; approx. 14 weeks of age

Dose / conc.:

0 ppm

Dose / conc.:

120 ppm

Remarks:

equivalent to 8.4 to 10.7 mg/kg bw/d (males)
and 8.0 to 17.1 mg/kg bw/d (females)

Dose / conc.:

300 ppm

Remarks:

equivalent to 20.7 to 26.1 mg/kg bw/d (males)
and 20.2 to 39.6 mg/kg bw/d (females)

Dose / conc.:

750 ppm

Remarks:

equivalent to 50.5 to 62.8 mg/kg bw/d (males)
and 49.8 to 101.2 mg/kg bw/d (females)

No. of animals per sex per dose:

25 in P0 and P1, respectively

Control animals:

yes, plain diet

Details on study design:

- Dose selection rationale: preliminary studies with male and female rats

- Rationale for animal assignment:
P animals:
The male and female animals were randomly allocated to treatment groups by a stratified randomization procedure based on body weight and were individually identified within the groups by earmarks. Each cage was identified by a group-related coloured card.

F1 animals:
Selection of weaned F1a pups to form F1 generation was made as follows: after all the F1a pups were weaned, one to three male and one to three female pups were selected from each litter - a minimum of 25 males and females per group - using a system of randomly drawn cards.
Selected F1 animals were identified by a combination of the litter number and Arabic numerals, if necessary. The animals were earmarked to ensure individual identification. Each cage was identified by a group-related coloured card.

Positive control:

not applicable

Parental animals: Observations and examinations:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: daily

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: daily

BODY WEIGHT: Yes
- Time schedule for examinations: weekly during pre-mating period; inseminated females were weighed on days 0, 6, 15, and 20 of gestation and lactating females on days 1, 4, 7, 14, and 21 of lactation

FOOD CONSUMPTION AND COMPOUND INTAKE:
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: Yes; weekly during pre-mating period and following same intervals as body weight assessment during gestation and lactation period for females.
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: No

WATER CONSUMPTION AND COMPOUND INTAKE: No

Oestrous cyclicity (parental animals):

Estrous cyclicity was not evaluated.

Sperm parameters (parental animals):

Parameters examined in all male parental generations:
testis weight, epididymis weight

Litter observations:

STANDARDISATION OF LITTERS
- Performed on day 4 postpartum: yes
- If yes, maximum of 8 pups/litter (4/sex/litter as nearly as possible); excess pups were killed and discarded.

PARAMETERS EXAMINED
The following parameters were examined in F1 / F2 offspring:
number and sex of pups, stillbirths, live births, postnatal mortality, presence of gross anomalies, weight gain, physical or behavioural abnormalities

GROSS EXAMINATION OF DEAD PUPS:
yes, for external and internal abnormalities; possible cause of death was determined for pups born or found dead.

ASSESSMENT OF DEVELOPMENTAL NEUROTOXICITY: No

ASSESSMENT OF DEVELOPMENTAL IMMUNOTOXICITY: No

Postmortem examinations (parental animals):

SACRIFICE
- Male animals: All surviving animals after delivery of litters sired.
- Maternal animals: All surviving animals after lactation period of 21 d

GROSS NECROPSY
- Gross necropsy consisted of external and internal examinations including the cervical, thoracic, and abdominal viscera.

HISTOPATHOLOGY / ORGAN WEIGHTS
The tissues indicated below were prepared for microscopic examination:
target organs, testes, epididymides, prostate, and seminal vesicles in males and ovaries, uterus, cervix, and vagina in females
Organ weights were not determined.

Postmortem examinations (offspring):

SACRIFICE
- The F1 offspring not selected as parental animals and all F2 offspring were sacrificed after weaning.
- These animals were subjected to postmortem examinations: gross necropsy but not histopathology

GROSS NECROPSY
- Gross necropsy consisted of external and internal examinations including the cervical, thoracic, and abdominal viscera

Statistics:

For body weight, body weight gain, litter weight, and mean pup weight, the analysis of variance was performed with one factor TREATMENT. In case of suspected significance, the four groups were compared at each time by the Newman-Keuls test for multiple group comparisons (p < 0.05). The statistical evaluation was performed with the standard software package SAS (Statistical Analysis System).

Reproductive indices:

The mating performance (in days) was calculated for each group as:
Sum of days until successful insemination divided by the Number of inseminated animals

The fecundity index (in per cent) was calculated for each group as:
Number of pregnant animals divided by the Number of inseminated animals multiplied by 100

The insemination index (in per cent) was calculated for each group as:
Number of inseminated animals divided by the Number of paired animals multiplied by 100

The fertility index (in per cent) for male and female animals was calculated for each group as:
Number of males shown to be fertile divided by the Number of males mated multiplied by 100
And:
Number of pregnant females divided by the number of mated females multiplied by 100

The gestation index (in per cent) was calculated for each group as:
Number of females with live pups divided by Number of pregnant animals multiplied by 100

Offspring viability indices:

The live birth index (in per cent) was calculated for each litter as:
Number of pups alive day 1 divided by Total number of pups born multiplied by 100

The viability indices (in per cent) were calculated for each litter as:
Number of pups alive day 4/7/14/21 divided by the Number of pups alive day 1/4*/7/14 multiplied by 100

The weaning index (in per cent) was calculated for each litter as:
Number of pups alive day 21 divided by the Number of pups alive day 4* multiplied by 100

Percentage sex ratio was calculated as:
Number of males divided by the Number of pups multiplied by 100 and Number of females divided by the number of pups multiplied with 100

*) number of pups alive on day 4 post-partum after adjustment of litter size

Clinical signs:

no effects observed

Description (incidence and severity):

Males: No treatment-related clinical signs could be observed.

Females: No treatment-related clinical signs could be observed.

Dermal irritation (if dermal study):

not examined

Mortality:

mortality observed, non-treatment-related

Description (incidence):

There were no treatment-related mortalities of the parental animals (P0).
One female of the P0 generation (animal no. 186) of group 4 (750 ppm) died on day 9 post-partum. Necropsy showed findings in the spleen, kidneys, urinary bladder, and lungs.
The occurrence of one death is considered to be incidental.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

Males: Body weight gain during the pre-mating period was slightly reduced in group 3 (300 ppm) and clearly reduced in group 4 (750 ppm) during the treatment period.

Females: Body weight gain of females during the pre-mating treatment, the gestation, and the lactation period was comparable in all groups.

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

Mean food consumption of group 4 (750 ppm) males was slightly reduced during the pre-mating treatment period. Mean food consumption of group 2 (120 ppm) and group 3 (300 ppm) males throughout the pre-mating treatment period was comparable with the control.

Mean food consumption of P0 females was generally similar in all groups throughout pre-mating treatment period, gestation, and lactation.

Food efficiency:

not examined

Water consumption and compound intake (if drinking water study):

not examined

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

not examined

Histopathological findings: non-neoplastic:

no effects observed

Description (incidence and severity):

Two males in group 1 (Control) and one male in group 4 (750 ppm) had atrophy of the seminiferous tubules of the testes. The group 4 male also had an absence of sperm in one epididymis. A small focus of chronic inflammation was observed in the prostate of one group 1 male.

Lesions observed in the females were: an ovarian cyst in one group 1 female, dilated lumens of the uterus in three females of group 1 and four females of group 4, an implantation site in the uterus of one female of group 4, acute inflammation in the uterus of one female of group 4, chronic inflammation in the uterus of one female in group 1, one endometrial stromal polyp of the uterus in each of the groups 1 and 4, and minimal accumulations of acute inflammatory cells in the cervix of four females in group 1 and ten females in group 4.

Histopathological findings: neoplastic:

no effects observed

Other effects:

no effects observed

Reproductive function: oestrous cycle:

not examined

Reproductive function: sperm measures:

no effects observed

Reproductive performance:

no effects observed

Description (incidence and severity):

There was no effect of treatment with test item on mating performance of fertility.

Duration of gestation:
All pregnant animals littered on day 21 or 22 of gestation. The mean duration of gestation was normal in all groups.

Number of pups: The live birth index was slightly reduced in group 4. Between days 1 and 4 p. p. pup losses were observed in all groups. After adjustment of litter size (day 4 p.p.) pup loss was similar in all groups.

The sex ratio was similar in all groups on days 1 and 21 of lactation.

Key result

Dose descriptor:

LOAEL

Effect level:

50.5 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male

Basis for effect level:

body weight and weight gain

food consumption and compound intake

Key result

Dose descriptor:

NOAEL

Effect level:

20.7 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male

Basis for effect level:

body weight and weight gain

food consumption and compound intake

Key result

Dose descriptor:

LOAEL

Effect level:

> 49.8 - < 101.2 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

female

Basis for effect level:

body weight and weight gain

Key result

Dose descriptor:

NOAEL

Effect level:

> 20.2 - < 39.6 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

female

Basis for effect level:

body weight and weight gain

Key result

Critical effects observed:

no

Clinical signs:

no effects observed

Description (incidence and severity):

No treatment-related changes in appearance, behaviour, and general condition were observed.

Dermal irritation (if dermal study):

not examined

Mortality:

mortality observed, non-treatment-related

Description (incidence):

One P1 male animal of group 4 (750 ppm) died on day 36 after start of mating; necropsy showed the right kidney developed as a tumour. This finding was considered to be incidental.

Body weight and weight changes:

no effects observed

Description (incidence and severity):

Males:
Body weight gain of P1 males during the pre-mating treatment period was slightly lower in group 4 (750 ppm) than in the concurrent control group.
In group 2 (120 ppm) and group 3 (300 ppm) mean body weight gain during the pre-mating treatment period was comparable with the control group.

Females:
Mean body weight gain of females during the pre-mating treatment, the gestation, and the lactation period was comparable in all groups.

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

Mean food consumption was slightly reduced throughout most of the pre-mating treatment period in P1 males of group 4 (750 ppm).
In groups 2 and 3 of P1 males and in all dose groups of P1 females, mean food consumption was comparable with the control group.

Food efficiency:

not examined

Water consumption and compound intake (if drinking water study):

not examined

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

no effects observed

Description (incidence and severity):

Necropsy of P1 males and females revealed a few isolated findings in all groups (e.g. hydronephrosis and/or dilatation of the renal pelvis, or testis enlarged or reduced, or small cyst on the urinary bladder, or cyst on the right ovary or right uterine horn developed rudimentarily). These findings were considered to be not related to treatment.

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

no effects observed

Description (incidence and severity):

Atrophy of seminiferous tubules was observed in one male each in groups 1 (Control) and 4 (750 ppm). One male in group 4 had an absence of sperm in one epididymis.
Dilatation of the uterus was observed in three females in group 1 and nine females in group 4.

Histopathological findings: neoplastic:

not examined

Other effects:

no effects observed

Reproductive function: oestrous cycle:

not examined

Reproductive function: sperm measures:

no effects observed

Reproductive performance:

no effects observed

Description (incidence and severity):

Mating performance and reproductive indices were comparable in all groups.

Duration of gestation:
The mean duration of gestation was normal in all groups.

Number of pups:
The live birth index was slightly lower in group 3 (300 ppm) and especially in group 4 (750 ppm).
Between days 1 and 4 p.p. pup losses were observed in all groups. After adjustment of litter size (day 4 p.p.) pup loss was similar in all groups.

The sex ratio was similar in all groups on days 1 and 21 of lactation.

Key result

Dose descriptor:

LOAEL

Effect level:

62.8 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male

Basis for effect level:

body weight and weight gain

food consumption and compound intake

Key result

Dose descriptor:

NOAEL

Effect level:

26.1 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male

Basis for effect level:

body weight and weight gain

food consumption and compound intake

Key result

Dose descriptor:

LOAEL

Effect level:

> 52.7 - < 90.4 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

female

Basis for effect level:

body weight and weight gain

Key result

Dose descriptor:

NOAEL

Effect level:

> 20.3 - < 34 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

female

Basis for effect level:

body weight and weight gain

Key result

Critical effects observed:

no

Clinical signs:

no effects observed

Dermal irritation (if dermal study):

not examined

Mortality / viability:

no mortality observed

Body weight and weight changes:

no effects observed

Description (incidence and severity):

There was no effect of treatment on post-natal growth. Mean pup weight in the treated groups was comparable with the control group.

Food consumption and compound intake (if feeding study):

not examined

Food efficiency:

not examined

Water consumption and compound intake (if drinking water study):

not examined

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

Urinalysis findings:

not examined

Sexual maturation:

not examined

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

no effects observed

Description (incidence and severity):

Macroscopic examination of pups died or sacrificed revealed no treatment-related changes.

Histopathological findings:

not examined

Other effects:

no effects observed

Description (incidence and severity):

Concerning all developmental landmarks examined (pinna unfolding, hair growth, incisor eruption, eye opening) its mean onset in the dose groups was comparable to the control group.
The employed functional tests (pupillary reflex, startle response) revealed no effect of treatment.
One pup of group 4 (750 ppm) showed externally an aplasia of the tail. The incidence of one malformation was considered to be incidental.

Behaviour (functional findings):

not examined

Developmental immunotoxicity:

not examined

Key result

Dose descriptor:

LOAEL

Generation:

F1

Effect level:

> 750 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Remarks on result:

not determinable due to absence of adverse toxic effects

Key result

Dose descriptor:

NOAEL

Generation:

F1

Effect level:

> 750 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Remarks on result:

not determinable due to absence of adverse toxic effects

Key result

Critical effects observed:

no

Clinical signs:

no effects observed

Dermal irritation (if dermal study):

not examined

Mortality / viability:

no mortality observed

Body weight and weight changes:

no effects observed

Description (incidence and severity):

From day 1 to 14 p.p. mean pup weight was similar in all groups. On day 21 p.p. mean pup weight of group 3 (300 ppm) and group 4 (750 ppm) was slightly lower than in the control group. This finding was considered to be incidental.

Food consumption and compound intake (if feeding study):

not examined

Food efficiency:

not examined

Water consumption and compound intake (if drinking water study):

not examined

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

Urinalysis findings:

not examined

Sexual maturation:

not examined

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

no effects observed

Description (incidence and severity):

Macroscopic examination of F2 pups died or sacrificed revealed no treatment-related changes.

Histopathological findings:

not examined

Other effects:

no effects observed

Description (incidence and severity):

One F2 pup of group 2 (120 ppm) showed an exophthalmia and one of group 3 (300 ppm) showed a hydronephrosis at necropsy. The occurrence of these malformations was considered to be incidental.
The onset of all physical parameters examined (pinna unfolding, hair growth, incisor eruption, eye opening) was comparable in all groups.
The employed functional tests (pupillary reflex, startle response) revealed no effect of treatment. One male pup in group 2 (120 ppm) showed blindness on the right eye. This finding was considered to be incidental.

Behaviour (functional findings):

not examined

Developmental immunotoxicity:

not examined

Key result

Dose descriptor:

LOAEL

Generation:

F2

Effect level:

> 750 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Remarks on result:

not determinable due to absence of adverse toxic effects

Key result

Dose descriptor:

NOAEL

Generation:

F2

Effect level:

> 750 ppm (nominal)

Based on:

test mat.

Sex:

male/female

Remarks on result:

not determinable due to absence of adverse toxic effects

Key result

Critical effects observed:

no

Key result

Reproductive effects observed:

no

Table 1       Multigeneration Reproduction Toxicity Study in Rats: Parental Effects

Parameter			Dose level [ppm]
			0		120		300		750		Dose-response +/-
		Genera­tion	m	f	m	f	m	f	m	f	m	f
Number of animals per group			25	25	25	25	25	25	25	25
Clinical Observations	Incidence
Injury on phalanx/tail/paw		F0	1	0	3	1	0	0	0	0	-	-
Injury in the eye			0	0	0	0	1	0	0	1	-	-
Swelling of ear			0	0	0	0	0	2	0	1	-	-
Loss of fur			0	0	0	0	0	0	0	0	-	-
Injury on phalanx/tail/paw		F1	0	1	1	1	1	1	0	0	-	-
Injury in the eye			0	0	0	0	0	0	0	0	-	-
Swelling of ear			0	0	0	0	1	0	0	0	-	-
Loss of fur			0	1	0	0	0	0	0	0	-	-
Mortality	Incidence	F0	0	0	0	0	0	0	0	1	-	-
Body weight gain	[g]
Week of treatment 1 to 14		F0	350.8	/	354.6	/	340.0	/	325.8	/	-	/
Week 1 to mating			/	121.4	/	121.6	/	131.0	/	124.2	/	-
Gestation day 0 to 20^1)			/	120.4	/	117.5	/	111.1	/	112.5	/	-
Lactation day 1 to 21^2)			/	14.8	/	17.0	/	19.0	/	26.6	/	-
Week of treatment 1 to 11		F1	350.6	/	373.8	/	355.6	/	331.8	/	-	/
Week 1 to mating			/	151.4	/	157.6	/	162.0	/	159.6	/	-
Gestation day 0 to 20^1)			/	115.4	/	113.6	/	108.9	/	114.5	/	-
Lactation day 1 to 21			/	21.0	/	23.4	/	31.5	/	37.4*	/	-
Food consumption (mean)	[g]
Week of treatment 1 to 14		F0	28.5	/	28.6	/	28.2	/	26.7*	/	-	/
Week 1 to mating			/	ne	/	ne	/	ne	/	ne	/	-
Gestation day 0 to 20^1)			/	ne	/	ne	/	ne	/	ne	/	-
Lactation day 1 to 21^2)			/	ne	/	ne	/	ne	/	ne	/	-
Week of treatment 1 to 14		F1	25.9	/	26.8	/	26.4	/	24.3*	/	-	/
Week 1 to mating			/	ne	/	ne	/	ne	/	ne	/	-
Gestation day 0 to 20^1)			/	ne	/	ne	/	ne	/	ne	/	-
Lactation day 1 to 21^2)			/	ne	/	ne	/	ne	/	ne	/	-

 

  Table 2 Multigeneration study in rats: Reproductive performance

Parameter			Dose level [ppm]
			0				120		300		750		Dose-response +/-
			historical control		concurrent control
		Genera­tion	m	f	m	f	m	f	m	f	m	f	m	f
Number of animals per group			25-30	25-30	25	25	25	25	25	25	25	25
Reproductive Performance
Number of inseminated animals		F0	/	--	/	25	/	25	/	23	/	24	/	-
		F1	/	--	/	25	/	25	/	25	/	25	/	-
Number of pregnant animals		F0	/	--	/	23	/	24	/	22	/	22	/	-
		F1	/	--	/	24	/	22	/	24	/	23	/	-
Number of animals with litters		F0	/	--	/	23	/	23	/	22	/	22	/	-
		F1	/	--	/	24	/	22	/	24	/	23	/	-
Insemination index	[%]	F0	93.3-100.0		100		100		92		96		-
		F1	76.0-100.0		100		100		100		100		-
Fecundity index	[%]	F0	73.9-96.7		92		96		95.7		91.7		-
		F1	68.4-100.0		96		88		96		92		-
Fertility index	[%]	F0	73.7-96.7		92		96		88		88		-
		F1	52.0-100.0		96		88		96		92		-
Gestation index	[%]	F0	95 0-100.0		100		95.8		100		100		-
		F1	96.0-100.0		100		100		95.8		95.7		-
Mean number of implantation sites		F0	12.3-15.5		13.6		14.5		14.0		13.3		-
		F1	12.0-15.7		14.2		14.0		13.7		14.3		-
Mean duration of gestation	[days]	F0	21-23		21.7		21.9		21.9		22.0		-
		F1	21-23		21.7		21.9		22.0		21.9		-

 

Table 3 Multigeneration reprotoxicity study: Litter development 

Parameter			Dose level [ppm]
			0				120		300		750		Dose-response +/-
			historical control		concurrent control
		Genera­tion	m	f	m	f	m	f	m	f	m	f	m	f
Number of animals per group					25	25	25	25	25	25	25	25
Live birth index		F1pups	50.0-100.0		95.3		96.9		95.2		87.8		-
		F2pups	11.1-100.0		94.5		97.0		89.1		80.3		-
Total litter losses		F1pups	--		3		0		1		3
		F2pups	--		9		3		4		4
Number of pups/litter found alive	Day 1	F1pups	1-20		12.3		12.5		11.9		10.9		-
		F2pups	0-19		12.7		12.7		11.2		9.9		-
	Day 4	F1pups	0-19		11.3		11.8		10.2		9.5		-
		F2pups	0-19		10.2		10.7		9.7		7.2		-
	Day 7^3)	F1pups	0-14		6.9		7.6		6.9		7.0		-
		F2pups	0-15		5.1		6.7		5.5		5.2		-
	Day 21	F1pups	0-14		6.4		7.0		6.4		6.2		-
		F2pups	0-11		3.6		5.6		3.8		4.2		-
Viability index (%)	day 1 to 4	F1pups	--		90.8		95.2		85.3		85.7		-
	day 4 to 7		--		91.5		95.1		92.5		94.6		-
	day 7 to 14		--		89.0		92.5		91.9		90.5		-
	day 14 to 21		--		100.0		98.5		100.0		97.4		-
	day 1 to 4	F2pups	--		77.8		84.8		88.6		70.7		-
	day 4 to 7		--		70.8		84.5		76.0		84.4		-
	day 7 to 14		--		53.1		79.7		66.2		76.4		-
	day 14 to 21		--		76.0		97.6		88.5		100.0		-
Mean Pup weight [g]	Day 1	F1pups	4.3-8.3		6.0		6.2		6.0		5.9		-
		F2pups	4.1-8.8		5.5		6.0*		5.9		5.7		-
	Day 4	F1pups	3.8-12.4		7.7		8.0		7.8		8.2		-
		F2pups	3.7-12.7		6.3		7.5*		7.0		7.2*		-
	Day 21	F1pups	9.9-60.0		39.5		40.5		38.4		37.8		-
		F2pups	15.3-55.6		37.3		40.7		33.9		32.6		-

 

¹⁾         day of pregnancy

²⁾         day post-partum

³⁾         adjustment of litter size at day 4

*          statistically significantly different from control, p<0.05

ne        no effect

 

Conclusions:

In this two generation study, groups of 25 male and female rats of the Sprague Dawley strain in each of two generations were given test item admixed to the diet at concentrations of 0, 120, 300, and 750 ppm continuously from the start of treatment until necropsy. Slight toxicity in the P male animals such as reduced body weight gain and reduced food consumption during the pre-mating treatment period was observed at 300 and 750 ppm. Body weight gain and food consumption were also slightly reduced in F1 males of the high dose group (750 ppm) during the pre-mating treatment period. There was no evidence of toxicity in either of the two generations of animals given diet containing test item at a concentration of 120 ppm. Life birth index was slightly reduced in either generation at 750 ppm. The postnatal development of the offspring during the lactation period was, however, not affected. There were no effects on fertility or general reproductive performance over two successive generations in animals given test item in the diet at concentrations of 120, 300, and 750 ppm.

Executive summary:

Groups of 25 male and female rats of the Sprague Dawley strain in each of two generations were given test item admixed to the diet at concentrations of 120, 300, and 750 ppm continuously from the start of treatment until necropsy. A further group of 25 males and 25 females, given untreated diet, were applied as control.
After a 14 weeks pre-mating treatment period, the parental animals in each generation were mated and the females were allowed to rear their offspring to weaning.

Results can be summarized as follows:

1. There were no abnormalities of clinical condition in the parental animals in either generation considered to be associated with treatment. Necropsy revealed no treatment-related findings.

2. Treatment with the test item at 300 and 750 ppm was associated with reduced body weight gain in P male animals during the pre-mating treatment period.

At 750 ppm the body weight gain of the F1 male animals was also slightly reduced during the pre-mating treatment period.

3. At 750 ppm the mean food consumption of the P and F1 male animals was slightly reduced during the pre-mating treatment period.

4. There was no effect of treatment in either generation on mating performance or fertility. 

5. Live birth index was slightly reduced in either generation at 750 ppm. Post-natal viability was however not affected.Post-natal growth of the offspring of the treated P and F1 animals was comparable to the controls.

6. Physical and functional development of the offspring of the treated animals was similar to the controls in both generations.

In conclusion, administration of the test item by admixture to the basic powdered diet at concentrations of 300 and 750 ppm elicited slight toxicity in the P male animals (reduced body weight gain and reduced food consumption -group 4 only - during the pre-mating treatment period). Body weight gain and food consumption were also slightly reduced in F1 males of the high dose group (750 ppm) during the pre-mating treatment period.

There was no evidence of toxicity in either of the two generations of animals given diet containing test item at a concentration of 120 ppm.

Life birth index was slightly reduced in either generation at 750 ppm.The postnatal development of the offspring during the lactation period was however not affected. There were no effects on fertility or general reproductive performance over two successive generations in animals given test item in the diet at concentrations of 120, 300, and 750 ppm.

Effect on fertility: via oral route

Endpoint conclusion:

no adverse effect observed

Effect on fertility: via inhalation route

Endpoint conclusion:

no study available

Effect on fertility: via dermal route

Endpoint conclusion:

no study available

Additional information

Two generation study in rats

Groups of 25 male and female rats of the Sprague Dawley strain in each of two generations were given the test item admixed to the diet at concentrations of 120, 300, and 750 ppm continuously from the start of treatment until necropsy.

A further group of 25 males and 25 females, given untreated diet, acted as control.

After a 14 weeks pre-mating treatment period, the parental animals in each generation were mated and the females were allowed to rear their offspring to weaning.

Results can be summarized as follows:

1. There were no abnormalities of clinical condition in the parental animals in either generation considered to be associated with treatment. Necropsy revealed no treatment-related findings.

2. Treatment with the test item at 300 and 750 ppm was associated with reduced body weight gain in P male animals during the pre-mating treatment period. At 750 ppm the body weight gain of the F1 male animals was also slightly reduced during the pre-mating treatment period.

3. At 750 ppm the mean food consumption of the P and F1 male animals was slightly reduced during the pre-mating treatment period.

4. There was no effect of treatment in either generation on mating performance or fertility.

5. Live birth index was slightly reduced in either generation at 750 ppm. Post-natal viability was however not affected. Post-natal growth of the offspring of the treated P and F1 animals was comparable to the controls.

6. Physical and functional development of the offspring of the treated animals was similar to the controls in both generations.

 

In conclusion, administration of the test item by admixture to the basic powdered diet at concentrations of 300 and 750 ppm elicited slight toxicity in the P male animals (reduced body weight gain and reduced food consumption -group 4 only - during the pre-mating treatment period). Body weight gain and food consumption were also slightly reduced in F1 males of the high dose group (750 ppm) during the pre-mating treatment period. There was no evidence of toxicity in either of the two generations of animals given diet containing the test item at a concentration of 120 ppm. Life birth index was slightly reduced in either generation at 750 ppm. The postnatal development of the offspring during the lactation period was however not affected. There were no effects on fertility or general reproductive performance over two successive generations in animals given the test item in the diet at concentrations of 120, 300, and 750 ppm.

Effects on developmental toxicity

Description of key information

Available data on developmental toxicity in the rat, mouse and rabbit indicate that the test item does not induce developmental toxicity or teratogenicty.

Link to relevant study records

Reference

Reference 1

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

1986-03-19 to 1986-12-01

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

comparable to guideline study

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 414 (Prenatal Developmental Toxicity Study)

Qualifier:

equivalent or similar to guideline

Guideline:

EPA OPP 83-3 (Prenatal Developmental Toxicity Study)

GLP compliance:

no

Limit test:

no

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Lot/batch No.of test material: P 2710-8511-R100

Species:

rat

Strain:

Sprague-Dawley

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Wiga GmbH
- Age at study initiation: sexually mature
- Weight at study initiation: 175 - 245 g (females)
- Housing: individually after mating
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: at least one week

ENVIRONMENTAL CONDITIONS
- Temperature: 20 - 25 °C
- Humidity: 40 - 70 %
- Photoperiod: 12/12 hrs dark / hrs light

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on exposure:

PREPARATION OF DOSING SOLUTIONS:
Test article was daily prepared es solution in corn oil. Separate preparations were made for each dose level.

VEHICLE
- Justification for use and choice of vehicle: good solubility of test item
- Concentration in vehicle: 0, 2.0, 5.0, 12.5 mg/mL
- Amount of vehicle: 10 mL/kg bw/d

Analytical verification of doses or concentrations:

no

Details on mating procedure:

- Impregnation procedure: cohoused
- M/F ratio per cage: 1 : 4
- Length of cohabitation: overnight
- Proof of pregnancy: sperm in vaginal smear referred to as day 0 of pregnancy

Duration of treatment / exposure:

ten consecutive days (gestation day 6 to 15)

Frequency of treatment:

daily

Duration of test:

animals were necropsied at gestation day 20

Dose / conc.:

0 mg/kg bw/day (actual dose received)

Dose / conc.:

20 mg/kg bw/day (actual dose received)

Dose / conc.:

50 mg/kg bw/day (actual dose received)

Dose / conc.:

125 mg/kg bw/day (actual dose received)

No. of animals per sex per dose:

Control: 38
Low Dose: 28
Mid Dose: 33
High Dose: 30

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: Preliminary study
- Rationale for animal assignment: randomly allocation immediatly after mating

Maternal examinations:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: twice daily

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: daily

BODY WEIGHT: Yes
- Time schedule for examinations: evaluation on gestation day 0, 6, 10, 15, 20

FOOD CONSUMPTION AND COMPOUND INTAKE: No

WATER CONSUMPTION AND COMPOUND INTAKE: No

POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day 20
- Organs examined: ovaries and uteri
- Data recorded: live foetuses, early resorptions, late resorptions, dead foetuses, individual foetal weights, sex of foetuses
- Intrauterine deaths were classified as follows: Early resorptions showed decidual or placental tissues only; Late resorptions showed embryonic or foetal tissue in addition to placental tissue but excluded foetuses dying in utero within approximately two days prior to the terminal kill; Dead foetuses included only the foetuses dying in utero within approximately the last two days.

Ovaries and uterine content:

The ovaries and uterine content was examined after termination: Yes
Examinations included:
- Gravid uterus weight: Yes
- Number of corpora lutea: Yes
- Number of implantations: Yes
- Number of early resorptions: Yes
- Number of late resorptions: Yes

Fetal examinations:

- External examinations: Yes: all per litter
- Soft tissue examinations: Yes: half per litter
- Skeletal examinations: Yes: half per litter
- Head examinations: No
- Other: Structural deviations were classified as:
- Malformations: rare and/or probably lethal e.g. hydrocephaly.
- Variations: changes which regularly occur also in control groups and which are not of functional significance.
- Retardations: delayed development as compared with the normal development at a particular point of time.

Statistics:

Data were processed where appropriate to give mean values, group mean values and standard deviations.
Group mean values for implantations, intra-uterine deaths and post-implantation losses were calculated in two ways:
Mean A: all animals with live foetuses at termination
Mean B: all surviving animals that provided evidence of pregnancy including those showing total intra-uterine deaths
For litter and mean foetal weights only Mean A was calculated.
Group mean calculations were normally based on individual values except for foetal weights where calculations were based on litter means.
All values expressed as a percentage were first calculated within the litter and then summarized per group as the mean of individual litter percentages (except sex ratio).

Group mean body weight, group mean body weight gain, and group mean foetal weight were statistically analysed using the Student's t-test.

All tests (control group versus dose groups) were carried out at 0.1 per cent, 1 per cent, and 5 per cent significance levels.

Indices:

Percentage pre-implantation loss was calculated for each litter as:
Number of corpora lutea - number of implantations divided by the Number of corpora lutea multiplied by 100

Percentage post-implantation loss was calculated for each litter as:
Number of implantations - number of live foetuses divided by the Number of implantations multiplied by 100

Percentage sex ratio was calculated as:
Number of males divided by Number of foetuses multiplied by 100
or
Number of females divided by Number of foetuses multiplied by 100

Clinical signs:

no effects observed

Description (incidence and severity):

No treatment-related clinical signs were observed in the treated animals.

Dermal irritation (if dermal study):

not examined

Mortality:

mortality observed, non-treatment-related

Description (incidence):

One animal in group 2 (20 mg/kg bw/d) died on day 8 of gestation probably due to improper gavaging.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

In group 4 (125 mg/kg), body weight gain was statistically significantly reduced from day 6 to 10 of gestation. From day 10 onwards, weight gain was comparable with the control group. At 20 and 50 mg/kg (group 2 and 3) body weight gain was comparable with the control group in spite of statistical significances found for group 3.

Food consumption and compound intake (if feeding study):

not examined

Food efficiency:

not examined

Water consumption and compound intake (if drinking water study):

not examined

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

no effects observed

Description (incidence and severity):

Occasional minor findings at necropsy of the remaining animals killed on day 20 of gestation were detected in all groups including the controls.
Macroscopic examination at necropsy showed no treatment-related changes.

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

not examined

Histopathological findings: neoplastic:

not examined

Other effects:

no effects observed

Number of abortions:

no effects observed

Pre- and post-implantation loss:

no effects observed

Description (incidence and severity):

There was no effect of treatment on implantations. Intergroup variations in pre-implantaion loss were not compound-related.
When all intra-uterine deaths are included the post-implantation loss was increased in group 3 (50 mg/kg bw/d) and group 4 (125 mg/kg bw/d) by the occurrence of 100 per cent intra-uterine death in two and one animal, respectively. This finding is considered to be incidental.

Total litter losses by resorption:

no effects observed

Early or late resorptions:

no effects observed

Dead fetuses:

effects observed, non-treatment-related

Description (incidence and severity):

Two animals in group 3 (50 mg/kg) and one animal in group 4 (125 mg/kg) showed 100 per cent intra-uterine death at necropsy.
The mean number of total intra-uterine death calculated from animals with live foetuses in utero at necropsy was comparable in all groups.

Changes in pregnancy duration:

not examined

Description (incidence and severity):

Migrated Data from removed field(s)
Field "Effects on pregnancy duration" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsMaternalAnimals.MaternalDevelopmentalToxicity.EffectsOnPregnancyDuration): no effects observed

Changes in number of pregnant:

no effects observed

Description (incidence and severity):

Pregnancy was not affected by treatment.

Other effects:

no effects observed

Key result

Dose descriptor:

NOAEL

Effect level:

50 mg/kg bw/day (actual dose received)

Based on:

test mat.

Basis for effect level:

body weight and weight gain

Key result

Dose descriptor:

LOAEL

Effect level:

125 mg/kg bw/day (actual dose received)

Based on:

test mat.

Basis for effect level:

body weight and weight gain

Key result

Abnormalities:

no effects observed

Fetal body weight changes:

no effects observed

Description (incidence and severity):

The mean foetal weight was comparable in all groups.
Migrated Data from removed field(s)
Field "Fetal/pup body weight changes" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsFetuses.FetalPupBodyWeightChanges): not examined

Reduction in number of live offspring:

no effects observed

Changes in sex ratio:

no effects observed

Description (incidence and severity):

The sex distribution in the treated groups was comparable with the control group.

Changes in litter size and weights:

no effects observed

Description (incidence and severity):

The mean number of foetuses per dam was comparable in all groups.

Changes in postnatal survival:

not examined

External malformations:

no effects observed

Description (incidence and severity):

On control foetus showed externally one finger of the right forelimb reddened.
In group 3 (50 mg/kg bw/d) one foetus showed viscerally a cleft palate and bilateral anophthalmia.
In group 4 (125 mg/kg bw/d) two foetuses with malformations were observed. One foetus showed a scoliosis and the second an open eye and a shortened mandible.

The nature and low incidence of these defects were such that their occurrence must be considered incidental.

Skeletal malformations:

no effects observed

Description (incidence and severity):

The incidence of skeletal variations was comparable in all groups.
However, in group 4 (125 mg/kg), a higher incidence of incompletely ossified cranial bones was observed. This delayed ossification is probably only a temporary condition which can be an incidental finding or is due to other reasons than an embryotoxic effect, e.g. decreased maternal body weight gain during the early treatment period.

Visceral malformations:

no effects observed

Description (incidence and severity):

Visceral variations as dilatation of the renal pelvis were observed in one foetus of group 2 (20 mg/kg bw/d) and 3 (50 mg/kg bw/d).

Other effects:

no effects observed

Key result

Dose descriptor:

NOAEL

Effect level:

> 125 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

male/female

Remarks on result:

not determinable due to absence of adverse toxic effects

Key result

Abnormalities:

no effects observed

Key result

Developmental effects observed:

no

Conclusions:

Oral administration of test item at a dose level of 125 mg/kg bw/d by oral route during the period of organogenesis (day 6 to 15 of gestation) revealed slight maternal toxicity in form of reduced body weight gain from day 6 to 10 p.c. An embryotoxic effect, especially a teratogenic effect, was not observed. Dose levels of 20 and 50 mg/kg bw/d did not elicit maternal toxicity, embryotoxicity, or teratogenicity.

Executive summary:

Groups of 28, 33, or 30 sexually mature and mated female Sprague Oawley Albino rats received test item by oral route at dosages of 20, 50, or 125 mg/kg bw/d for ten consecutive days from day 6 to 15 of qestation. A further group of 38 rats which received the vehicle (corn oil) over the same period served as the control group. The animals were sacrificed on day 20 of gestation. Results can be summarized as follows:

1. No effects of dosing on clinical condition and no treatment-related necropsy findings were observed in the treated animals or in the control

2. Treatment with the test item at 125 mg/kg bw/d was associated with a slight reduction of body weight gain from day 6 to 10 p.c.

3. There was no effect of treatment on pregnancy incidence, pre-implantation loss, or post-implantation loss.

4. There was no effect of treatment with the test item on the number, weight, or sex of the foetuses.

5. There was no indication for an effect of treatment on the incidence of malformations.

At 125 mg/kg, a slightly retarded ossification of cranial bones was observed.This finding is probably only a temporary condition which can be an incidental finding or is due to other reasons than an embryotoxic effect.

Administration of test item at a dose level of 125 mg/kg bw/d by oral route during the period of organogenesis (day 6 to 15 of gestation) revealed slight maternal toxicity in form of reduced body weight gain from day 6 to 10 p.c. An embryotoxic effect, especially a teratogenic effect, was not observed. Administration of test item at dose levels of 20 and 50 mg/kg bw/d did not elicit maternal toxicity, embryotoxicity, or teratogenicity.

Reference 2

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

1988-10-27

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 414 (Prenatal Developmental Toxicity Study)

Version / remarks:

1981

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPP 83-3 (Prenatal Developmental Toxicity Study)

Version / remarks:

1982

Deviations:

no

GLP compliance:

yes

Limit test:

no

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Lot/batch No.of test material: P 100

Species:

mouse

Strain:

NMRI

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Wiga GmbH
- Age at study initiation: females were approx. 5 to 8 weeks old; males were sexually mature
- Weight at study initiation: 20.1 to 30.0 g (females)
- Housing: mated females were housed individually
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: at least seven days

ENVIRONMENTAL CONDITIONS
- Temperature: 19 - 25 °C
- Humidity: 30 -70 %
- Photoperiod: 12/ 12 hrs dark / hrs light

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on exposure:

PREPARATION OF DOSING SOLUTIONS: The test article was daily prepared as a solution in the vehicle (corn oil). Separate preparations were made for each dose level.

VEHICLE
- Justification for use and choice of vehicle: same as used in preliminary study
- Concentration in vehicle: 2.0, 5.0, 12.5 mg/mL
- Amount of vehicle: 10 mL/kg bw/d

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Samples for analysis were taken from dose formulations for each dose level in the first week of treatment and in the last week of treatment of the initially treated 25 animals per group, as well as in the first week of treatment for the additionally treated ten further animals per group, deep-frozen immediately after formulation, and were sent to the study sponsor for analysis.

Details on mating procedure:

- Impregnation procedure: cohoused
- M/F ratio per cage: 1 : 4
- Length of cohabitation: overnight
- Proof of pregnancy: vaginal plug referred to as day 0 of pregnancy

Duration of treatment / exposure:

from gestation day 6 to 15 (inclusive)

Frequency of treatment:

daily

Duration of test:

necropsy at GD 18

Dose / conc.:

0 mg/kg bw/day (actual dose received)

Dose / conc.:

20 mg/kg bw/day (actual dose received)

Dose / conc.:

50 mg/kg bw/day (actual dose received)

Dose / conc.:

125 mg/kg bw/day (actual dose received)

No. of animals per sex per dose:

35

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: preliminary dose-range finding study
- Rationale for animal assignment: random

Maternal examinations:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: twice daily

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: daily

BODY WEIGHT: Yes
- Time schedule for examinations: on days 0, 6 - 15 and 18 post coitum

FOOD CONSUMPTION AND COMPOUND INTAKE: YES
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: Yes
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: No

WATER CONSUMPTION AND COMPOUND INTAKE: No

POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day 18
- Organs examined: uteri and ovaries

Ovaries and uterine content:

The ovaries and uterine content was examined after termination: Yes
Examinations included:
- Gravid uterus weight: No
- Number of corpora lutea: Yes
- Number of implantations: Yes
- Number of early resorptions: Yes
- Number of late resorptions: Yes
- Other: live fetuses; dead fetuses; individual fetus weights, sex of fetuses

Fetal examinations:

- External examinations: Yes: all per litter
- Soft tissue examinations: Yes: all per litter
- Skeletal examinations: Yes: half per litter
- Head examinations: No

Structural deviations were classified as:
- Malformations: rare and/or probably lethal e.g. hydrocephaly.
- Variations: changes which regularly occur also in control groups and which are not of functional significance.

Statistics:

Data were processed where appropriate to give mean values, group mean values, and standard deviations.
Group mean values for implantations, intra-uterine deaths, and postimplantation losses were calculated in two ways:

Mean A: all animals with live fetuses at termination
Mean B: all surviving animals that provided evidence of pregnancy including those showing total intra-uterine deaths

Group mean calculations were normally based on individual data, except for group mean fetal weights where calculations were based on litter means.
All values expressed as a percentage were first calculated within the litter and then summarized per group as the mean of individual litter percentages.

For body weight, body weight gain, food consumption, litter weight, and mean fetal weight per litter (overall, males, females), the analysis of variance was performed with one factor TREATMENT, followed by the Student-Newman-Keuls test for multiple group comparisons.

Number of corpora lutea, number of implantations, number of intra-uterine deaths, number of fetuses, preimplantation loss, postimplantation loss, and proportion of male fetuses were statistically analysed using the Wilcoxon rank sum test. In case of suspected significance (probability > chi square < 0.05), the four groups were compared two by two using the Kruskal Wallis Analysis of Variance.
All tests were performed using a two-sided risk and a significance level of p smaller or equal 0.05.
All statistical analyses were performed using the standard software package SAS® (Statistical Analyses System, Release 6.02).

Indices:

The preimplantation loss was calculated for each litter as:
Number of corpora lutea - number of implantations divided by the Number of corpora lutea multiplied with 100

The postimplantation loss was calculated for each litter as:
Number of implantations - number of live fetuses divided by the Number of implantations multiplied with 100

The sex ratio was calculated for each litter as:
Number of males divided by Number of fetuses multiplied with 100
And
Number of females divided by Number of fetuses multiplied with 100

Clinical signs:

no effects observed

Description (incidence and severity):

No treatment-related clinical signs were observed in the treated animals.

Dermal irritation (if dermal study):

not examined

Mortality:

mortality observed, non-treatment-related

Description (incidence):

Mortalities were observed in all groups.
One control animal died on day 8 post-coitum, and necropsy showed clear signs of an intubation error.
One animal of group 2 (20 mg/kg bw/d) died on day 18 post-coitum. Necropsy showed left lobe of the lung dark red in colour and covered with clotted blood and thorax filled with clotted blood.
Two animals of group 3 (50 mg/kg bw/d) died on day 10 or 9 post-coitum, respectively, due to improper gavaging.
Three animals of group 4 (125 mg/kg bw/d) died on day 10 post-coitum. Two of these animals showed signs in the lungs probably due to improper gavaging. The third animal showed no abnormalities at necropsy but an intubation error cannot be excluded.
All mortalities are considered not to be related to treatment.

Body weight and weight changes:

no effects observed

Description (incidence and severity):

Body weight gains were similar in all groups.

Food consumption and compound intake (if feeding study):

no effects observed

Description (incidence and severity):

There was no effect of treatment on food consumption.

Food efficiency:

not examined

Water consumption and compound intake (if drinking water study):

not examined

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

no effects observed

Description (incidence and severity):

Macroscopic examination at necropsy showed no treatment-related changes. One animal of group 2 (20 mg/kg bw/d) showed a dilatation of the renal pelvis at necropsy and one animal of group 4 (125 mg/kg bw/d) showed left corpora lutea covered with a vesicle containing reddish fluid. These findings are considered to be incidental.

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

not examined

Histopathological findings: neoplastic:

not examined

Other effects:

no effects observed

Number of abortions:

no effects observed

Pre- and post-implantation loss:

no effects observed

Description (incidence and severity):

Implantations were not affected by treatment with test item.
There was no effect of treatment with the test item on the incidence of intra-uterine death.
The highest incidence was observed in the control group when including animals with 100 per cent intra-uterine deaths.

Total litter losses by resorption:

no effects observed

Early or late resorptions:

no effects observed

Dead fetuses:

no effects observed

Description (incidence and severity):

Two animals of group 1 (control) and one animal of group 3 (50 mg/kg bw/d) showed 100 per cent intra-uterine deaths at necropsy.

Changes in pregnancy duration:

no effects observed

Description (incidence and severity):

One animal of group 3 (50 mg/kg bw/d) littered on day 18 post-coitum.
Migrated Data from removed field(s)
Field "Effects on pregnancy duration" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsMaternalAnimals.MaternalDevelopmentalToxicity.EffectsOnPregnancyDuration): not examined

Changes in number of pregnant:

no effects observed

Description (incidence and severity):

Pregnancy was not affected by treatment.

Other effects:

no effects observed

Key result

Dose descriptor:

NOAEL

Effect level:

> 125 mg/kg bw/day (actual dose received)

Based on:

test mat.

Remarks on result:

not determinable due to absence of adverse toxic effects

Key result

Dose descriptor:

LOAEL

Effect level:

> 125 mg/kg bw/day (actual dose received)

Based on:

test mat.

Remarks on result:

not determinable due to absence of adverse toxic effects

Key result

Abnormalities:

no effects observed

Fetal body weight changes:

not examined

Description (incidence and severity):

Migrated Data from removed field(s)
Field "Fetal/pup body weight changes" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsFetuses.FetalPupBodyWeightChanges): not examined

Reduction in number of live offspring:

no effects observed

Description (incidence and severity):

The mean number of fetuses per dam was comparable in all groups.

Changes in sex ratio:

no effects observed

Description (incidence and severity):

There was no effect of treatment on fetal sex distribution.

Changes in litter size and weights:

no effects observed

Description (incidence and severity):

The mean fetal weight was comparable in all groups.

Changes in postnatal survival:

not examined

External malformations:

no effects observed

Description (incidence and severity):

External malformations as bent tail or exencephalocele were observed in one fetus each of group 3 (50 mg/kg) and group 4 (125 mg/kg). Cleft palate was observed in one control fetus, in one fetus of group 3 (50 mg/kg bw/d), and in two fetuses of group 4 (125 mg/kg bw/d).

Skeletal malformations:

no effects observed

Description (incidence and severity):

Two control fetuses and one fetus of group 3 (50 mg/kg bw/d) showed a scoliosis.
Further skeletal defects as fused ribs were observed in two fetuses of group 2 (20 mg/kg bw/d) and in one fetus of group 3 (50 mg/kg bw/d), and one additional fetus each of groups 2 and 3 showed the vertebral column in the thoracic region partly malformed.
The nature and incidence of these defects are considered to be incidental. The incidence of skeletal variations was comparable in all groups.

Visceral malformations:

no effects observed

Other effects:

no effects observed

Key result

Dose descriptor:

LOAEL

Effect level:

125 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

male/female

Remarks on result:

not determinable due to absence of adverse toxic effects

Key result

Dose descriptor:

NOAEL

Effect level:

> 125 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

male/female

Remarks on result:

not determinable due to absence of adverse toxic effects

Key result

Abnormalities:

no effects observed

Key result

Developmental effects observed:

no

Conclusions:

Administration of test item by oral gavage during the period of organogenesis (day 6 to 15 of gestation) at dose levels of 20, 50, and 125 mg/kg bw/d to mice, did not elicit maternal toxicity, embryotoxicity, or teratogenicity.

Executive summary:

Groups of 35 sexually mature and mated female NMRI mice received test item by oral gavage at dosages of 20, 50, or 125 mg/kg bw/d for ten consecutive days from day 6 to 15 post-coitum, inclusive. A further group of 35 mice which received the vehicle (corn oil) over the same period served as the control group. The animals were sacrificed on day 18 post-coitum. Results are summarized as follows:

1. No effects of dosing on clinical condition and no treatment-related necropsy findings were observed in the animals.
2. There was no effect of treatment on maternal body weight gain.
3. There was no effect of treatment on food consumption.
4. There was no effect of treatment on pregnancy incidence, preimplantation loss, or postimplantation loss.
5. There was no effect of treatment on the number, weight, and sex distribution of the fetuses.
6. There was no indication for an effect of treatment on the incidence of malformations.

Administration of test item by oral gavage during the period of organogenesis (day 6 to 15 of gestation) at dose levels of 20, 50, and 125 mg/kg bw/d did not elicit maternal toxicity, embryotoxicity, or teratogenicity.

Reference 3

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

1992-08-17

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EPA OPP 83-3 (Prenatal Developmental Toxicity Study)

Deviations:

no

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 414 (Prenatal Developmental Toxicity Study)

GLP compliance:

yes

Limit test:

no

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: 910662.69

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Hazleton Research Products, Inc.
- Weight at study initiation: approx. 3359 - 3400 g
- Housing: individually
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: 22 d

ENVIRONMENTAL CONDITIONS
- Temperature: 61 - 70 °F (equals 16.1 - 21.1 °C)
- Humidity: 40 - 60 %
- Photoperiod: 12 / 12 hrs dark / hrs light

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on exposure:

PREPARATION OF DOSING SOLUTIONS:
The test article was ground using a mortar and pestle and passed through a No. 40 mesh sieve prior to weighing. A specified amount of test item for each dose group was weighed into a calibrated beaker. An appropriate amount of the vehicle was added to each beaker and the mixtures were stirred. A sufficient quantity of vehicle was then added to each mixture to achieve the desired concentrations. Each mixture was stirred for an additional 10 minutes and dispensed into daily aliquots. The dosing mixtures were prepared fresh weekly and stored in amber bottles at room temperature. During each weekly preparation, a sufficient quantity of corn oil was also dispensed into daily aliquots for administration to control animals. Daily aliquots were stirred for 10 minutes prior to dispensation and continuously during dosing.

VEHICLE
- Justification for use and choice of vehicle: preliminary dose-range finding study
- Concentration in vehicle: 0, 4, 40, 100 mg/mL
- Amount of vehicle: 0.5 mg/kg bw/d

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Prior to study initiation, the analytical method supplied by the Sponsor was validated and homogeneity and stability analyses were performed on concentrations of the test article which were expected to encompass those used in the study (5 and 500 mg/mL). Although a concentration of 4 mg/mL was ultimately utilized for the low-dose group, further stability and homogeneity testing was not considered necessary since the test article was stable and homogeneous in the vehicle at concentrations as low as 5 mg/mL. Each fresh dosing preparation was analyzed for test article concentration.
Prestudy analytical chemistry evaluations indicated that the test item was homogeneous and stable in corn oil for up to eight days when stored at room temperature. Analysis of dosing preparations resulted in average test article recoveries ranging from 97.8 to 103.8% indicating that the mixtures were accurately prepared.

Details on mating procedure:

- Impregnation procedure: artificial insemination
- Verification of same strain and source of both sexes: yes
- Proof of pregnancy: day of insemenation is referred to as day 0 of pregnancy

Duration of treatment / exposure:

from gestation day 6 to 18

Frequency of treatment:

daily

Duration of test:

necropsy on GD 29

Dose / conc.:

0 mg/kg bw/day (actual dose received)

Dose / conc.:

2 mg/kg bw/day (actual dose received)

Dose / conc.:

20 mg/kg bw/day (actual dose received)

Dose / conc.:

50 mg/kg bw/day (actual dose received)

No. of animals per sex per dose:

20

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: preliminary dose-range finding study
- Rationale for animal assignment: random

Maternal examinations:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: daily

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: daily; in addition, during treatment period, animals were observed between one-half hour and two hours following dosing.

BODY WEIGHT: Yes
- Time schedule for examinations: GD 0, 6, 9, 12, 15, 19, 24, and 29

FOOD CONSUMPTION AND COMPOUND INTAKE: Yes
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: Yes
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: No

WATER CONSUMPTION AND COMPOUND INTAKE: No

POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day 29
- Organs examined: thoracic abdominal and pelvic cavities were opened and tha vicera examined. Representatitve tissue samples from internal lesions were preserved.

Ovaries and uterine content:

The ovaries and uterine content was examined after termination: Yes
Examinations included:
- Gravid uterus weight: Yes
- Number of corpora lutea: Yes
- Number of implantations: Yes
- Number of early resorptions: Yes
- Number of late resorptions: Yes

Fetal examinations:

- External examinations: Yes: all per litter
- Soft tissue examinations: Yes: half per litter
- Skeletal examinations: Yes: half per litter
- Head examinations: No

Statistics:

Continuous maternal and fetal data, including body weights, body weight gain, food consumption, number of fetuses, implantation sites and corpora lutea, were analyzed using one way analysis of variance (ANOVA) followed by Dunnett's test. The Mann-Whitney U test was used to compare post-implantation loss and resorptions, Fetal sex ratios were analyzed using the Chi-square test, Fisher's Exact test was used to analyze the incidence and number of fetal malformations and variations utilizing the dam (litter) as the experimental unit. All analyses were two-tailed with a minimum significance level of 5%.

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

For the control female which died, clinical observations including salivation, fecal stain and decreased activity were noted following dosing on the day of death. No clinical signs were observed for this female prior to this time.

In animals which died or were sacrificed during the study at the 50 mg/kg bw/d level, clinical observations were noted for several days prior to death or sacrifice. These findings included few feces, no feces, fecal stain, soft stools, mucoid stools, fecal stain, and reddish colored material in the cage/tray. Additional findings for the female sacrificed moribund at the 50 mg/kg bw/d level included reddish colored material in cage/tray, yellow or white crusty material around the nose and/or mouth, emaciation, dehydration, unkempt appearance and prostration.

Clinical signs of toxicity were also observed for surviving females at the 50 mg/kg bw/d level. These findings included few feces, no feces and soft stools. No adverse clinical signs were observed in surviving females of the control, 2 or 20 mg/kg bw/d groups.

Dermal irritation (if dermal study):

not examined

Mortality:

mortality observed, treatment-related

Description (incidence):

Two 50 mg/kg bw/d females were found dead and one 50 mg/kg bw/d female was sacrificed moribund during the study. These deaths/sacrifices occurred between gestation days 21 and 23. In addition, one 50 mg/kg bw/d female aborted on gestation day 24 and one control female died due to an apparent gavage error on gestation day 13. All other females survived to scheduled sacrifice on gestation day 29.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

Mean maternal body weights and body weight gain were comparable among the control, 2 and 20 mg/kg bw/d groups throughout the study.
At the 50 mg/kg bw/d level, statistically significant body weight loss occurred during gestation days 6-9, 9-12, 15-19 and 6-19, while slight weight loss occurred during gestation days 12-15. Mean body weights at the 50 mg/kg bw/d level were slightly lower on gestation days 12 and 15, and statistically lower on gestation day 19 as compared to control females. During the final days of gestation (days 24-29), body weight gain of the 50 mg/kg bw/d females was markedly higher than controls indicating that a partial recovery had occurred from the earlier reductions in body weight gain.

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

Food consumption calculated as grams/animal/day and grams/kg/day was comparable between the control, 2 and 20 mg/kg bw/d groups throughout the study. Food consumption at the 50 mg/kg bw/d level was statistically lower during gestation days 6-9, 9-12, 12-15, 15-19, and 6-19 as compared to controls. During the final days of gestation (days 24-29), food consumption of the 50 mg/kg bw/d females was markedly higher than controls indicating that a partial recovery had occurred from the earlier reductions in food consumption.

Food efficiency:

not examined

Water consumption and compound intake (if drinking water study):

not examined

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

effects observed, treatment-related

Description (incidence and severity):

Necropsy findings for the two females found dead at the 50 mg/kg bw/d level (#1849 and #1850) included dry red or wet dark brown matting in the urogenital area and base of tail, wet light brown matting around nose, several tan areas on the external and cut surfaces of the liver, and left apical lobe of the lung light brown.
For the female sacrificed moribund at the 50 mg/kg bw/d level (#1885), necropsy findings included yellow or white crusty material around the nose and/or mouth, small thymus, pale kidneys, eroded areas and multiple black foci on the mucosal surface of the stomach, blackish-red mucoid material mixed with food contents in the stomach, and multiple tan areas on the external and cut surfaces of the liver.
Gross necropsy findings for the 50 mg/kg bw/d female which aborted (#1866) were limited to green fluid contents in the cecum and hairloss on the hindlimbs and abdominal area.
For the control female found dead during the study (#1825), gross necropsy findings consisted of wet dark brown matting in the anogenital area, clear wet matting around the mouth, dark red areas on the caudal lobes of the lungs, and dark red foci on the glandular mucosa of the stomach.
In surviving animals, gross necropsy observations were generally unremarkable.

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

not examined

Histopathological findings: neoplastic:

not examined

Other effects:

no effects observed

Number of abortions:

no effects observed

Pre- and post-implantation loss:

no effects observed

Total litter losses by resorption:

no effects observed

Early or late resorptions:

no effects observed

Dead fetuses:

no effects observed

Changes in pregnancy duration:

not examined

Description (incidence and severity):

Migrated Data from removed field(s)
Field "Effects on pregnancy duration" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsMaternalAnimals.MaternalDevelopmentalToxicity.EffectsOnPregnancyDuration): not examined

Changes in number of pregnant:

no effects observed

Description (incidence and severity):

The pregnancy rate was 85% in the 20 mg/kg bw/d group and 95% in the control, 2 and 50 mg/kg bw/d groups.

Description (incidence and severity):

There were no statistical differences in cesarean section parameters among the groups.
However, in the 50 mg/kg bw/d group, a slight increase in mean post-implantation loss and a corresponding decrease in the mean number of viable fetuses was observed. All other cesarean section parameters were comparable between the control and treatment groups.

Key result

Dose descriptor:

LOAEL

Effect level:

50 mg/kg bw/day (actual dose received)

Based on:

test mat.

Basis for effect level:

body weight and weight gain

clinical signs

food consumption and compound intake

mortality

Key result

Dose descriptor:

NOAEL

Effect level:

20 mg/kg bw/day (actual dose received)

Based on:

test mat.

Basis for effect level:

body weight and weight gain

clinical signs

food consumption and compound intake

mortality

Key result

Abnormalities:

no effects observed

Fetal body weight changes:

not examined

Description (incidence and severity):

Migrated Data from removed field(s)
Field "Fetal/pup body weight changes" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsFetuses.FetalPupBodyWeightChanges): not examined

Reduction in number of live offspring:

no effects observed

Changes in sex ratio:

no effects observed

Changes in litter size and weights:

no effects observed

Changes in postnatal survival:

not examined

External malformations:

no effects observed

Skeletal malformations:

no effects observed

Visceral malformations:

no effects observed

Other effects:

no effects observed

Details on embryotoxic / teratogenic effects:

No statistically significant differences in fetal malformation or developmental variations were noted among the groups. A low incidence of dissimilar malformations known to occur spontaneously in this strain of rabbit were observed in each study group, including the control. The incidence of developmental variations was generally similar among the groups.

Key result

Dose descriptor:

NOAEL

Effect level:

> 50 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

male/female

Remarks on result:

not determinable due to absence of adverse toxic effects

Key result

Dose descriptor:

LOAEL

Effect level:

> 50 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

male/female

Remarks on result:

not determinable due to absence of adverse toxic effects

Key result

Abnormalities:

no effects observed

Key result

Developmental effects observed:

no

Conclusions:

Oral administration of the test item at doses of 2, 20, and 50 mg/kg bw/d to New Zealand White rabbits from gestation day 6 to 18 resultet in substantial signs of maternal toxicity at the highest dose, such as clinical signs, mortality and reduced body weight and food consumption. Whereas at the mid and low dose no signs of toxicity were observed. Effects of embryotoxicity or teratogenicity were not observed in any of the treated groups.

Executive summary:

This study was performed to detect and evaluate the potential embryotoxic or teratogenic effects of the test item when administered orally to pregnant rabbits during the period of major organogenesis. The study design consisted of a vehicle control and three treatment groups. Each group contained twenty artificially inseminated female New Zealand White rabbits. The test article was suspended in Mazola® corn oil and administered at dosage levels of 2, 20 and 50 mg/kg bw/d from gestation day 6 through gestation day 18. All doses were given at a constant volume of 0.5 mL/kg. Control animals were administered com oil under the same experimental conditions and at an equivalent dose volume. The animals were observed daily for clinical signs of toxicity. Body weights were measured on gestation days 0, 6, 9, 12, 15, 19, 24, and 29 and food consumption was measured daily. Surviving animals were sacrificed on gestation day 29 and subjected to cesarean section. Fetuses were weighed individually, sexed and examined for external, visceral and skeletal abnormalities.

Substantial toxicity was produced by the test article at the 50 mg/kg bw/d level where two females died and one was sacrificed moribund between gestation days 21 and 23. Additional indications of maternal toxicity at the 50 mg/kg bw/d level consisted of adverse clinical signs, body weight loss and reduced food consumption. One female of the 50 mg/kg bw/d group aborted on gestation day 24. In contrast to these changes, no adverse maternal effects were observed at the 2 or 20 mg/kg bw/d levels. There were no statistical differences in cesarean section parameters among the groups. However, at the 50 mg/kg bw/d level, there was a slight increase in mean post-implantation loss and a corresponding decrease in the mean number of viable fetuses. It is noteworthy that these differences occurred in the presence of substantial maternal toxicity. All other cesarean section parameters were comparable among the groups. No treatment-related malformations or developmental variations were observed in the study. Based on the results of this study, a dosage level of 20 mg/kg bw/d was considered a no-observed-effect level (NOEL) for maternal toxicity. A dosage level of 50 mg/kg bw/d was considered a NOEL for teratogenicity.

Effect on developmental toxicity: via oral route

Endpoint conclusion:

no adverse effect observed

Effect on developmental toxicity: via inhalation route

Endpoint conclusion:

no study available

Effect on developmental toxicity: via dermal route

Endpoint conclusion:

no study available

Additional information

Three developmental toxicity studies were conducted applying rat, rabbit, and mouse, respectively. None of them revealed adverse effects on fetal development or teratogenicity in the absence of considerable maternal effects in any dose. Thus, the highest dose tested can be considered as NOAELdevelopmental, which is the 50 mg/kg bw/d for rabbit and 125 mg/kg bw/d for both rat and mouse.

Developmental toxicity study, rat

Groups of 28, 33, or 30 sexually mature and mated female Sprague Dawley Albino rats received the test item by oral route at dosages of 20, 50, or 125 mg/kg bw/d for ten consecutive days from day 6 to 15 of gestation. A further group of 38 rats which received the vehicle (corn oil) over the same period served as the control group. The animals were sacrificed on day 20 of gestation.

After conclusion of the present study with the test item including the evaluation of the data, the results can be summarized as follows:

 

1. No effects of dosing on clinical conditions and no treatment-related necropsy findings were observed in the treated animals or in the control 

2. Treatment with the test item at 125 mg/kg was associated with a slight reduction of body weight gain from day 6 to 10 p.c. 

3. There was no effect of treatment on pregnancy incidence, pre-implantation loss, or post-implantation loss. 

4. There was no effect of treatment with the test item on the number, weight, or sex of the foetuses. 

5. There was no indication for an effect of treatment on the incidence of malformations.

At 125 mg/kg bw/d, a slightly retarded ossification of cranial bones was observed. This finding is probably only a temporary condition which can be an incidental finding or is due to other reasons than an embryotoxic effect. In summary, administration of the test item at a dose level of 125 mg/kg bw/d by oral route during the period of organogenesis (day 6 to 15 of gestation) revealed slight maternal toxicity in form of reduced body weight gain from day 6 to 10 p.c. An embryotoxic effect, especially a teratogenic effect, was not observed. Administration of the test item at dose levels of 20 and 50 mg/kg did not elicit maternal toxicity, embryotoxicity, or teratogenicity.

Developmental toxicity study, rabbit

This study was performed to detect and evaluate the potential embryotoxic or teratogenic effects of the test item when administered orally to pregnant rabbits during the period of major organogenesis. The study design consisted of a vehicle control and three treatment groups. Each group contained twenty artificially inseminated female New Zealand White rabbits. The test article was suspended in Mazola® corn oil and administered at dosage levels of 2, 20 and 50 mg/kg bw/d from gestation day 6 through gestation day 18. All doses were given at a constant volume of 0.5 mL/kg. Control animals were administered com oil under the same experimental conditions and at an equivalent dose volume. The animals were observed daily for clinical signs of toxicity. Body weights were measured on gestation days 0, 6, 9, 12, 15, 19, 24, and 29 and food consumption was measured daily. Surviving animals were sacrificed on gestation day 29 and subjected to cesarean section. Fetuses were weighed individually, sexed and examined for external, visceral and skeletal abnormalities.

Substantial toxicity was produced by the test article at the 50 mg/kg bw/d level where two females died and one was sacrificed moribund between gestation days 21 and 23. Additional indications of maternal toxicity at the 50 mg/kg bw/d level consisted of adverse clinical signs, body weight loss and reduced food consumption. One female of the 50 mg/kg bw/d group aborted on gestation day 24. In contrast to these changes, no adverse maternal effects were observed at the 2 or 20 mg/kg bw/d levels. There were no statistical differences in cesarean section parameters among the groups. However, at the 50 mg/kg bw/d level, there was a slight increase in mean post-implantation loss and a corresponding decrease in the mean number of viable fetuses. It is noteworthy that these differences occurred in the presence of substantial maternal toxicity. All other cesarean section parameters were comparable among the groups. No treatment-related malformations or developmental variations were observed in the study. Based on the results of this study, a dosage level of 20 mg/kg bw/d was considered a no-observed-effect level (NOEL) for maternal toxicity. A dosage level of 50 mg/kg bw/d was considered a NOEL for teratogenicity.

Developmental toxicity study, mouse

Groups of 35 sexually mature and mated female NMRI mice received test item by oral gavage at dosages of 20, 50, or 125 mg/kg bw/d for ten consecutive days from day 6 to 15 post-coitum, inclusive. A further group of 35 mice which received the vehicle (corn oil) over the same period served as the control group. The animals were sacrificed on day 18 post-coitum. Results are summarized as follows:

1. No effects of dosing on clinical condition and no treatment-related necropsy findings were observed in the animals.
2. There was no effect of treatment on maternal body weight gain.
3. There was no effect of treatment on food consumption.
4. There was no effect of treatment on pregnancy incidence, preimplantation loss, or postimplantation loss.
5. There was no effect of treatment on the number, weight, and sex distribution of the fetuses.
6. There was no indication for an effect of treatment on the incidence of malformations.

Administration of test item by oral gavage during the period of organogenesis (day 6 to 15 of gestation) at dose levels of 20, 50, and 125 mg/kg bw/d did not elicit maternal toxicity, embryotoxicity, or teratogenicity.

Justification for classification or non-classification

Classification, Labelling, and Packaging Regulation (EC) No 1272/2008
The available experimental test data are reliable and suitable for classification purposes under Regulation (EC) No 1272/2008. Based on available data on toxicity to reproductionn and developmental toxicity the test item is not considered to be classified according to Regulation (EC) No 1272/2008 (CLP), as amended for the eighth time in Regulation (EU) No 2016/918.